Find a bitter agent spray at the pet store, like bitter apple, and spray it on the leaves of the plant

They’ll eventually learn that the plants taste bad, and leave them alone (saved my Aloe from a very mouthy feline, as well as various fabrics from the golden retriever puppy)

Alternatively, put lemon or citrus scented spray on the plants, but i found that less effective compared to the bitter spray

You can also get them cat grass or silvervine sticks to chew on